Hi mate,
We check your logo image. It seems that the background is large, and the content (inner image) is small.
So I give you the suggestions:
1 . You have to re-cut your image to make sure that the inner image (main logo) will be larger
or
2 . We will raise the width for you and put in child theme. However the space in Menu will be changed also http://prntscr.com/lwsklg
So, please think then give me your solution for this
Regards,
Yame